JPH04269387A - Vane pump - Google Patents

Abstract

PURPOSE:To form a vane chamber displaying pump function into flexible structure. CONSTITUTION:Elastic bodies 11 are fitted, by means of bonding or the like, to the side wall part of a vane slit 15 provided at the circumferential part of a rotor 1 so as to enclose a vane 2. The vane 2 is enclosed in the vane slit 15 through these elastic bodies 11. A vane chamber is formed into flexible structure since the vane 2 can be displaced circumferentially by the influence of the elastic bodies 11. The fluctuation of delivery pressure is thereby reduced, and the sudden rise of oil pressure caused by the fluctuation of load pressure and the like can be absorbed.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vane pump for a power steering device, and in particular, the vane chamber has a flexible structure to reduce hydraulic pulsation.

0002

2. Description of the Related Art Most of the components of conventional vane pumps are made of metal such as iron. That is, as shown in Fig. 3, for example, the rotor 1, vane 2, cam ring 3, side plate 4, etc. that constitute the vane chamber (a) that performs the pump function are all made of iron-based metal and are considered as so-called rigid bodies. It is something that can be done. Therefore, when the vane pump starts operating, the members such as the rotor 1, vane 2, cam ring 3, etc. function as a pump.
In other words, it performs the actions of suction, expansion, compression, and discharge, but since the hydraulic oil (discharged oil) discharged in this way inherently has a pulsation phenomenon, these discharged oils are discharged into the hydraulic circuit. As the pressure increases, resonance phenomena such as surging may occur even in the hydraulic circuit due to the above-mentioned pulsation phenomenon.

0003

[Problem to be Solved by the Invention] In order to eliminate the above pulsation phenomenon, accumulators and the like are provided, but in general, existing accumulators are intended to deal with low frequency pulsations. It cannot cope with high frequency pulsations, etc. Therefore, an object of the present invention is to provide a vane pump for dealing with the above-mentioned high frequency pulsation phenomenon.

0004

[Means for Solving the Problems] In order to solve the above problems, in the present invention, a flexible structure is adopted for some of the members constituting the vane chamber. That is, in a vane pump consisting of a rotor, vanes, a cam ring, a housing, etc., an elastic body is provided in the vane slit of the rotor in which the vane is housed and slides, and the action of this elastic body causes the vane to move. This is intended to absorb shocks such as hydraulic pulsations that act on the vane when it performs its pumping function.

[0005]

[Operation] By adopting the above configuration, when the vane pump according to the present invention starts operating, the rotor 1 driven by the rotating shaft 6 rotates, as shown in FIG. The rotor 1 moves along the cam surface 31 of the cam ring, and performs a sliding movement within the vane slit 15 in the rotor 1. By the operation of these members that perform the pump function, the hydraulic oil sucked into the vane chamber (a) is expanded and compressed, and is intermittently discharged from the discharge port 41.

By the way, when the vane chamber (A) reaches the position of the discharge port 41, the discharged hydraulic fluid is raised to a constant pressure and is discharged all at once. Moreover, such a state is repeated intermittently every time the next vane chamber comes to the position of the discharge port 41. Therefore, in principle, the discharged oil exhibits a pulsating phenomenon, but in the present invention, since the elastic body 11 is provided in the vane slit portion 15 of the rotor 1, the vane 1 can move around the rotor 1. can be slightly displaced in the circumferential direction, so the volume of the vane chamber (A) changes in accordance with changes in the pressure of the vane chamber (A). Therefore, changes in the pressure of the hydraulic oil in the vane chamber (A) can be absorbed by changing the volume of the vane chamber (A). Further, even if the load pressure increases due to the operation of the power steering device, etc., and the sudden pressure increase in the vane chamber (a) occurs due to this pressure, the pressure change can be absorbed.

[0007]

[Example] Regarding the example according to the present invention, FIGS. 1 and 2
, will be explained based on FIG. First, its configuration is basically the same as the existing vane pump, as shown in FIG. That is, a rotating shaft 6 driven by output from an engine, a rotor 1 connected to the rotating shaft 6 by a spline or the like, a vane 2 housed in a vane slit 15 of the rotor 1, and the vane 2 and the above. A cam ring 3, which is located outside the rotor 1 and contributes to the formation of the vane chamber (a) together with the vane 2, rotor 1, etc., the vane 2,
The vane 2 is located on the side of the rotor 1 and cam ring 3.
, a side plate 4 that contributes to the formation of a vane chamber (a) together with the rotor 1, cam ring 3, etc., a front housing 5 and a rear housing (1) that house pump functional parts such as the vane 2, rotor 1, cam ring 3, side plate 4, etc. (not shown), etc.

In addition to these, the configuration of this embodiment has the following features. That is, as shown in FIG. 1, elastic bodies 11 made of soft plastic or the like are provided on both side walls of a vane slit 15 provided in a rotor 1 by means such as adhesion or baking. The elastic body 1
A slit plate 12 with a low coefficient of friction made of a metal piece or the like is provided inside the plate 1 by means of adhesion or baking as described above. A vane 2 similar to the existing vane is provided in the space formed by the two slit plates 12 so as to be slidable with respect to the two slit plates 12.

[0009] Also, the vane slit 15 of the vane 2
In addition to the above-mentioned structure, as a method of storing the rotor 1, there is also a method of coating the surface of the vane slit 15 of the rotor 1 with a resin having a low coefficient of friction, as shown in FIG. That is, the elastic body 11 is made of a soft resin having a low coefficient of friction and a certain elasticity, and is attached to the side wall of the vane slit 15 by coating, etc., the slit plate 12 is abolished, and the vane 2 is directly attached to the side wall of the vane slit 15. The structure is such that it comes into contact with a resin etc. with a low coefficient of friction.

As shown in FIGS. 1 and 2, the configuration in which the vanes 2 are accommodated in the vane slits 15 of the rotor 1 via the elastic bodies 11 does not necessarily have to be provided for each vane. A method may also be adopted in which every other one is stored via the elastic body 11. That is, for example, in each of the vane slits 1a, 1b, and 1c in FIG. 1, 1a and 1c may be coated with the elastic body 11, and 1b may have a conventional structure without using the elastic body.

Next, the operation of this embodiment having the above configuration will be explained. When the above vane pump starts operating,
The hydraulic oil sucked, expanded, and compressed in the vane chamber (A) consisting of the rotor 1, vane 2, cam ring 3, etc. becomes high-pressure discharge oil and is discharged from the discharge port 41 provided on the side plate 4. is supplied into the hydraulic circuit. That is, as described above, in the vane pump of this embodiment, high-pressure discharge oil is discharged every time the vane chamber (A) comes to the position of the discharge port 41, and therefore, the discharged hydraulic oil (discharge oil) has pressure pulsations. However, in the present invention, since the vane 2 is housed in the vane slit 15 of the rotor 1 via the elastic body 11,
While the vane 2 performs the pumping action, it is possible to make a small displacement in the circumferential direction of the rotor 1. That is, since the vane chamber (A) has a flexible structure, the volume of the vane chamber (A) can change, albeit minutely. Due to the effect of this minute volume change in the vane chamber (a),
Pressure pulsations in discharged oil are absorbed. In addition, if the negative pressurization suddenly increases due to the operation of the operating equipment and a sudden pressure increase occurs in the pump mechanism, it is also possible to absorb the pressure increase.

0012

[Effects of the Invention] According to the present invention, an elastic body is provided in the vane slit portion which is the vane housing portion of the rotor in a vane pump, and the vane is housed through the elastic body, thereby providing a vane chamber that performs the pump function. Since it has a flexible structure, even if a sudden increase in oil pressure acts on the pump mechanism due to an increase in negative pressurization, the increase in oil pressure can be absorbed by a change in the volume of the vane chamber. Furthermore, the effect of reducing the pressure pulsations of the discharged oil itself has been added, making it possible to reduce pulsations in the hydraulic circuit.

[Brief explanation of the drawing]

[Fig. 1] Rotor, vane, specific contents of the present invention,
FIG. 3 is a structural diagram showing a state in which an elastic body and the like are attached.

FIG. 2 is a structural diagram of another embodiment of the present invention in which the slit plate is omitted.

FIG. 3 is a cross-sectional view showing the basic configuration of a vane pump.

[Explanation of symbols]

1 Rotor 11 Elastic body 12 Slit plate 15 Vane slit 2 Vane 3 Cam ring 31 Cam surface 4 Side plate 41 Discharge port 5 Front housing 6 Rotation axis

Claims (1)

[Claims] Claim 1: In a vane pump consisting of a rotor, vanes, cam ring, housing, etc., an elastic body is provided on the side wall of a vane slit provided in the rotor for storing the vane, and the vane is inserted through the elastic body. What is claimed is: 1. A vane pump characterized in that the vane pump has a configuration in which the rotor is housed, and a vane slit portion having the elastic body is provided on the circumference of the rotor.